Vibration damper



July 21, 1931. A. F. STAMM 1,815,808

VIBRATION DAMPER Filed Jan. 16, 1930 v INVENTOR 44.7 :Siamm,

ATTORNEY raaeii egl, j

V 'binationsfhereih set forth claimed.)

.frial "Nogioseoo;filedaueve ber ai, meaty: x n er Se m nctE i d f hKKnohL-j QA'nIobjectofjmyinvention istoprovidea I I h he r ope ngflangeightnot occur,and I 4 ALEXANDER: ESTAMM F'DETR IT, MIdH-IG N ,j'vmmmaAMPER 7 hi invention relates t5 torsional ate-g tiondampersfor useonsha'fts ot any nature subjected to" torsional l'v ibration," and moreparticularly for use on automobile, airplane, j' 5 and s milar engnejsha'fts, and: it consists n the? construct ons; arrangementsand"'c0'm1-' v invention is designed fas an impfo' ment lover s the device disclosed n appl cation 0 for 5 Letters Patent on vibrat n dampenSetorsionaljvibr'ation damper which vrill'assure 15 the operationoftliejdamping' action at all "times arid will consequentlyd T s nc'vibm o ro o t the cntire'sPeed' j J rarigeofthe shaft to whichfit isapplied when i -i =pr p e e i omp n t i a ens a:

any'instant' speedfwithin said rangel As set f forth in the'ab'ovefnoted applicationrlfad 'j istab mp ng a'ccomp he y f e y?mounting friction shoes on the "rotatable Ni shaft; engageable withfrictional'surfaces integral with said, shaft, so that y, the freelymounted shoes dueto their inertia, rotate at" f ia consmnt speed, whilethe cooperating 'frictio'nal surfaces integral withthe shaft rotate atvariable speeds due to the torsional vibra- I 33' tio'rfs; and thisrelative movement dampens' out i the vibrations accordance with theforce of said vibrations" because of the "exc ertionon the shoesfand themasses settiiigj'up the torsional vilorations of centrifugal forcesduring the rotation 'These frictionalshoes i being subjectedtofcentrifugalforce with I consequent variationinthe frictionexistentbetiveenthe shoesv andthfeir cooperating surfacesaccording'tothe square of-the velocity vmof rotation ofsaid shaft and the torsionalI vibrations set up"insaidshaft being caused by the unequal forces"exerted therealong, whi'ch.,are also" greatly the result ofcenw trifugalforces, and varygaccording to the square or the velocityof rotation,'therehy provide an arrangement wherein the damping efiect; is; alwaysequal-gtfo -the vibratory "forcescausiiig the torsional vibration. It istherefore jobvious l-tha't 'when 1 the r damper is qpr'operlyproportioned to "dampen the torsional vibrations at agivenspeedyoffsaidand 'the torsional ivibration forces. In the use ofthedevice set forth in this I prior patent application itywas found that;

if the] friction I sectors or shoes were .nia'tlef large enough to have'thenecessary polar in'oment' of inert a to store up suiiicient energy eC mp t y; pen torsional vihration',

the frictional resisting moment inight' bel so great; that slippingbetween said shoes "and therefore; would bring about no damping action."I T Y c ln; attemptingto overcome this difiiculty, 1

I ha vefound that if the friction sectors o'r shoes] are coupled to an Iannular ring,'- the kinetic energy of said annular ring will hesuificient to, overcome the frictional adhesion 1 r I of the sectors orshoes to their cooperating flange and to bring; about slippagetherebetween with consequent dissipation ofthe torsionalvibratory forcesbetween said engaging frictional surfaces in the form of heat. Itis'therefore a primary object of my inven- 7 tion to provideaconstruction thatwill assure slippage between the friction shoesas wellas I variation in the frictional gforce according t0 the force of thetorsional vibrations.

A further object ofmyinvention is to pro vide 'a*torsional vibrationdamper which has;

notget out of order easily. r W

Further objects and advantages will ap-,1 pear'as thespecificationproceeds and thein' it vention will be more particularlydefined in" the appended claims. I r I An embodimentof invention isshown in the accompanyingdrawings forming part i of this application, inwhich 3 Figure 1 sa front elevational View of dev ce accord ng tomyinvention; and

is subjected to torsional vibration.

few parts, is simple to manufacture, and does I 5 i Figure 2 isavertical sectional View of'the 5 a device shown in Figure 1.' e v t a1,111, carrying out my invention, I make use j of any shaft 1,-forexample,.the.crank shaft e ofan automobile or, airplane engine, which'In the embodimentshown, the shaft lhas a 'gear 2mounted-thereon, an oilslinger3 positioned in front of said gearand anroil flangen1ember9'maybe secured to the pulley m mbe by mea s o tbs bolt 10V, o ay otheir stiitjable means. [This dislifl;

1 69 Preyides an annular wall 11' engagingi with .th'e' 7 Perip r Wallaaa l,.p f it nsdi sha relationtothe wall 7 definingin cooperation withthe walljan'd the peripheral wall 8, a a k which; is a apt d f icidnally nga the friction sectors or shoemembers" 12 which ride'therein.

-' These'friction sectorsor'shoes 12 form'an annular frictional-memberfwhich may be wbe described.-

7 composed, of any desired number of friction sectors or shoes ratherthanthefour shoesshown in this'zembodiment. i

"These shoes present frictional surfaces 13 'on'their outer peripheriesfor engagement with the; frictional surfaces 14k onv the inner -psr rh tthe p rip er W llis It is,

between these surfaces that the torsional via i ns reflamr e nd' ipa-tedin the form of. heat. Each of these sectorsis provided with a radialbore 1 5, which cooperates with other: members for an For s u ng slipp gt n. t e tr p? tional surfaces 13 and 14 on the members 12 and 8, theannular ring member 16, which 1 term the kineticenergy ring, isprovided. This rlng 'lsan unbroken annulus surround- 7 ing the shaft andpositioned within thecir'cle for'me djby the friction sectors or -shoes,and

V is protided withradialbores 1? which aline withithe bores 15'for thereception of coupl'ing means betweensaidmembers, Counter bores 18 areprov'ide'd' n communicat on with the bores :17

appear; 7

'Eor; coupling the ,members' 16 in r ve d Position; c pl n p s areprovided. A s'appears inithe. drawings,

these coupling pi nsllg engage through the bores 17 an'di115, and aresecured therein against longitudinal movement byJthe transverse pinmembers'QQ, "These-transverse pin o m mbers 20, engagai hroush,axialtb einthe annular ring. 16 and through bores 22 thl p n membe 9.-

opera sasfw to;

for a' ip rpose'thiat Will soon 7 f I To malntain the frictionsectors orshoes 12] of the peripheralwall 8 when the shaft is at rest, and toprevent shocks incident to the engagement of the walls 13 and 14 duringthe rapid acceleration of the velocity of r0- tation of the shaft, thespring members 23 are supplied, These spring member 23 seat inithecounter-bores 18 tofengage at'one of their ends the shoulders Qiforined'at the "base of'the 'counter-borexl8 and the inner- "peripheralsurfaces.25Iof1the friction sectors or shoes 12. This spring is of" thetype cominonl yikn'own as a compressionspring, and normallyurges thefriction shoesor sectors 12 outwardly fromth'e annular ring 16 and into.engagement with the friction surface 11 on the peripheral wall 8f j InproportiOning the parts and setting them up for use, the frictionsectors orshoes l 2fare so proportioned thatwhen operatively connectedwith, the. annular ring:1,6 and set into rotation therewith, they willexert just sufficientforc on the -"fri ctio'n surface 14 to dampenioutthe torsionalvibrations trans1nit-- ted through said surface; withoutexerting a great enough force]oil-said surfaceto prevent slippagebetweenfsaid shoes and said surface.. It is 'obviousthat thisforceexistent between the fricti'onsurfaces 13 and 14;

will vary accordingftothe speed of rotation v of the; shaft, andconsequent centrifugal forcesacting'upon said members. QIt is alsoobvious that the torsional Vibrations transmitted through the surface, li'when thedevice is used on shaftswhcrein rthe torsional feet exertedjbythe friction. sectors" or shoes, 1 ror example, in the application of myinvention to ashaftin which therequired frictional.resistinginoment is918.75 ihchlbs. at ,10 ratu's, could he arrived at as'follows;

The coefficient of friction between the friction, shoe IQ andMthe dampershell; 8 is'taken to be .l5a'fa ir value for cast ironfon'castiron,:with smooth unlubricated surfaces" Since, v i

1% frictional. resisting moment 0 co-eficient of friction F=icentrifugalforce R= outsideradiu OR .15 x? Theradius of 'gyration of the frictionshoe Then in frictional engagement with the surface it vibrations varyaccording to centrifugal force, will vary directly as the damping ef-,

W 'he're ri is eq ual to theradiusof theinner 3, the proportions of theap a s gi periphery' of the friction shoe and 42 is the V radius of theouter. periphery of said shoeQ I I For determining thefweight ofeachfriction' weuse the expressionfor the centrifugal 7 viously'setforth, toaccommodate the friction When the' shaft rotates, the annularring 16 rotate at'a substantially constant speed while the peripheralwall 8 and engaging friction surface 14, will respond to the torsionalvibrations in the. shaft and rotate at a constantly sectors 12' andtheannularring member, 16; i

force: j k varying speed. The torsional vibrations x F WV? f causing thevariationinsaidspeed will be i 32.215 I Y -frictionally braked anddampened, out by I (3 means of the engagement of said surface I j I W 5f the frlctlon sectors or shoes 12. The frictron- V a '1 .al forceexerted during this operation will W V 13 1 32 2 4 32 e vaig 51Sltieretofolre iet tfort 1n aecordancte 1 2' v y s .w1 e orsiona v1 raory orces ransmi i T I te'dthrough the peripheral member 8 and-the V i ffrictional surfacel v The weighto-r each friction shoe must be .562sprlngs 23 W Serve o a a the ,1b o v a shoes inengagement when the shaftis at rest w it The maximum'possible Weight of all shoes wh n Subjectedt unusually h accelera- Mi e f; I v I I tlOr-illalgql'lieg. n d. 1rd

- 1e1s ane iswevaa e oexcue b Q vflx 6X1(4- T F? 2; 9 v dirt, oil, andot he'r foreign m zitter from the T i of thkersectorisf' t t weirkin'gparts ofthe device.

03111112" I r J a 1. In a damper for use on shafts subjected y w 7 2.596 360 V to torsional vibrations, an annular frictional i, a5 7 p v pdeg- I, surface rotatablewith said shaft and adapted ,It is ide cided tousefour sectors with in to transmit. torsional v em i space betweenthee'nds sothat'theresulting h t; Shoes e g e e l h l u l erc Will ,beabout SSdcgreeSQ Z f f '$l annular i in: order to permit-this, uiespring'pressure tlng ald tw s d means ,shduld 10631001113 0 U coupllngsa d shoes to sa1d annular rlng com 1 f f prising radiallyextendingpinsengagingsaid p 92*88 ggya'gn s oesandsaid ring, 3

g 92 i 2.111 a damper "foruse on shafts jsubjected f vto torsionalvibrations, an annular rictiona ig- 32?? amen 9 n rf ih usurfacerotatable withsaidshaftahdadapted L T v88 2 i to transm ttorsional vibrations from sa d I i 4.32?=1.4;7 1i shaft, frlctlonshoes,,engageable with said a I frictional"surface} an annular ring, for i gThe total moment of inertia ofthefdamper mounting said friction shoes,and means for ring and sectors must .beAAT. j Y 1 coupling said shoes tosaid annular ring, com- The momentof' inertia of the ring'must beprisingradially extending pins engaging v 447-44753 r said shoes andsaid ring and compression I a springs mounted on said pins andinterposed I= rma(r -1'3 g between said ringand shoes. I 45 2 1 v Inadamper for use on shafts subjected l T i j to torsional vibrations, anannular frictional I W lere 7 15 m. l 3 i 9 9 surface rotatable withsaid shaft and adapted fiery of 31 ,o 1 to] transmit torsionalvibrations from said s ri Y 3.14 .00794 1 (4'.'1-25f-r ishaft, frictionshoeseng'ageable with saidf 5c 4 j 1 f frictional surface, eacli of'saidfshoes having 115 I K o a radial bore anannu ar ring ormountin I 2(?8 *7' );w. v p said friction shoes, radially extending pin 'f1'3.=49.6. a g rigicl on said annular ring for engagement in M a f; therespective radial bores of said shoes, and 55 I I V 1 v 1 g Y t gresilientmeansodisposed around said pins and The inside radius of, thering :is' 2% inches, between said ring and shoes. approximately; f l o]n ALEXANDER F. STAMM. ,The'use and operation of the'device isclearlyunderstood from the foregoing descrips t jtion: Thefanibeltpulley is modified as pre-' 1

